Thickness profiling of electron transparent aluminium alloy foil using convergent beam electron diffraction

Abstract

Convergent beam electron diffraction (CBED) was used to profile the thickness of aluminium alloys foils prepared by using the twinjet electropolishing method. The two-beam CBED condition was obtained by exciting the {200} and {111} aluminium diffracted g-vector. The aluminium alloy foil thicknesses were calculated at different distances from the sample hole edge. In areas where only one Kossel-Möllenstedt (K-M) minima fringe was obtained, the thickness was determined by matching the experimental with simulated convergent beam diffraction patterns. In areas far away from the sample edge, the thickness of foils was high enough to generate at least two (K-M) minima fringes, required for linear regression fitting.

Quantifying the thickness of WTe2 using atomic-resolution STEM simulations and supervised machine learning

“…49 For direct imaging of the layers, transmission electron microscopy (TEM) can image a cross section of a 2D material prepared by focused ion beam (FIB). 50,51 Other TEM-based thickness measurement methods utilize analysis of convergent beam electron diffraction (CBED) patterns, 52 diffraction or imaging tilt series, [53][54][55][56][57][58] or low-loss electron energy-loss spectroscopy (EELS). 59 Yet, these methods do not extract the information directly from a single atomic-resolution image, which would be desirable for ease of acquisition and analysis, especially because WTe 2 is highly air sensitive, [60][61][62][63][64][65] and to minimize the electron dose that damages beam-sensitive 2D materials.…”